New to me 86 WR400

Thanks Dukkman! My cover isn't that bad but the plate is a great idea. Did you seal under the plate too?

The real key to using JB Weld in a fluid area is to seal any JB surface that the skin has been sanded or ground off with epoxy or do not remove the skin to start with

Yep , bit of 3 bond just to make sure.
I wish I could take credit for the idea.
I bought my 240 first , the pump was shabby so I came up with the plate idea.
Then I bought my 400 and it already had a plate.

So I got it started briefly! Thanks to all you's for your help
Unfortunately I sheared the flywheel key because I didn't tighten the flywheel so I'll get another one tomorrow and try again.

really need to lap it then too

The bolt was only hand tightened- I'm sure that was the problem.
Is it possible to easily install a decompression lever on a liquid cooled motor?

that headstay is badass! you need to make us a batch of those..ill take one in 250 and 400/430!

Yeah I dig that mount as well. Looks stout.

Are the two front head nuts are stepped into the head stay?

Headstay doesn't work guys .
What it does is hide the problem until it's really bad.
Best cure is to fix the swingarm through the motor bolt/bushes .
Also make sure that the frame holes aren't elongated or you will never stop the vibes.

Yep ajcm those nuts are stepped to use the original studs.

Are those decompression valves currently available Dukkman?
Not clear on why a head stay would not work. Without one my old Triumph's shaking is considerably worse.
This assumes all the problems you mentioned have been implemented.

Euro
Can't find where I bought those deco's from but they were Harley ones.
Any chainsaw deco will work and there's a guy in NZ who is using Victa Mower ones because they are automatic and don't need resetting.

If you fix the back end/swing arm bolt the vibration goes away and you don't need the headstay anymore.
I made 2 of them .
One for my 400 and as I said after fixing the cause never needed the brace anymore.
The other was on my 240 and I sat down and learn't how to balance the motor which totally removed the vibs AND let the thing rev like a demented 80cc. [ entirely different bike ]

Thanks Dukkman! Balancing the engine is a little costly, isn't it? Haven't tackled the Triumph because of the cost. "O
Thanks for the deco info. "It only vibrates a little..."